1. Field of the Invention
This invention relates generally to internal combustion engines and more particularly to a novel reciprocating piston engine embodying a unique circular cam ring arrangement for converting the periodic power strokes of each engine piston to rotation of the engine rotor. The invention relates also to a novel opposed piston engine utilizing the cam ring conversion arrangement.
2. Discussion of the Prior Art
According to one of its broader aspects, the invention provides a unique circular cam ring mechanism for converting reciprocating motion of an engine piston to rotation of the engine rotor. In this regard, it will become evident as the description proceeds that this cam ring conversion mechanism may be utilized in a single piston engine or in a multiple piston engine wherein each cylinder contains a single piston. However, the mechanism is particularly suited and primarily intended for use in and a more limited aspect of the invention is concerned with an opposed piston engine. For this reason, the invention will be described in the context of such an engine.
In an opposed piston engine, each cylinder contains a pair of pistons having piston rods extending through the ends, respectively, of the cylinder and piston heads on the adjacent inner ends of the rods. These pistons form therebetween a combustion chamber which undergoes contraction upon inward movement of the pistons toward one another through compression strokes and expansion upon outward movement of the pistons through power strokes. A combustible medium, i.e., fuel/air mixture, is supplied to this combustion chamber by inward movement of the pistons through their compression strokes. The compressed medium is then ignited to drive the pistons outwardly through their power stroke. One advantage of such an engine is the ability to achieve a given compression ratio with a shorter stroke length than required in a conventional engine for efficient breathing.
The design of an opposed piston engine presents a major problem to which this invention is addressed. This problem concerns conversion of the reciprocating motion of the engine pistons to rotary motion of the engine rotor. A variety of motion conversion arrangements have been devised for this purpose. U.S. Pat. No. 2,558,349, for example, discloses an opposed piston engine with the form of motion conversion means for converting reciprocating piston motion to rotary motion of the engine rotor.